Fluid flow control apparatus for filter units in a filtration system

ABSTRACT

A unitary filtering device, wherein the mounting base contains an internal network of interconnected ducts having a first inlet duct and a first exit duct and a plurality of access holes each connected therewith, a second inlet duct and a second exit duct, and a valve channel individual to each of the first and second inlet and exit ducts. Anchor bolts are secured to the base and engaged by a clamp, gripping the outer surface of a hollow cylinder near one end, for sealing the one end against the base, in such a position that the access holes are surrounded thereby. A plurality of hollow tubular filter elements are each mounted at one end over a corresponding one of the access holes, with a top cover positioned over the other end of the cylinder and engaged by the anchor bolts for sealing the other end of the cylinder thereto. Plug-ended valve stems are mounted within each valve channel and are movable in longitudinal directions to either of two predetermined positions therein for establishing either a filtering route or a backwashing route within the device.

United States Patent Goodpasture [4 1 June 20, 1972 [54] FLUID FLOW CONTROL APPARATUS FOR FILTER UNITS IN A FILTRATION SYSTEM [72] lnventor: Kenneth Wayne Goodpasture, c/o Dixon Industrial Park, Dixon, 111. 61021 [22] Filed: July 29, 1970 [21] Appl.No.: 59,108

[56] References Cited UNITED STATES PATENTS 5/1928 Hart ..210/4l8 X 4/1968 Tipping 2/1928 Winslow et al.. 4/1948 Rayburn ..210/323 X o o o o e a .0 0. 0 0902090,.

Primary ExaminerFrank A. Spear, Jr. Attorney-James T. Whitesel 5 7] ABSTRACT A unitary filtering device, wherein the mounting base contains an internal network of interconnected ducts having a first inlet duct and a first exit duct and a plurality of access holes each connected therewith, a second inlet duct and a second exit duct, and a valve channel individual to each of the first and second inlet and exit ducts. Anchor bolts are secured to the base and engaged by a clamp, gripping the outer surface of a hollow cylinder near one end, for sealing the one end against the base, in such a position that the access holes are surrounded thereby. A plurality of hollow tubular filter elements are each mounted at one end over a corresponding one of the access holes, with a top cover positioned over the other end of the cylinder and engaged by the anchor bolts for sealing the other end of the cylinder thereto. Plug-ended valve stems are mounted within each valve channel and are movable in longitudinal directions to either of two predetermined positions therein for establishing either a filtering route or a backwashing route within the device.

7 Claims, 6 Drawing Figures PATENTEDJUHZO 1972 3, 670,895

SHEET 3 or 3 2% g IO! 12 RETURN HOSE LIQUID RETURN HOSE SOLUTION FLUID FLOW CONTROL APPARATUS FOR FILTER UNITS IN A FILTRATION SYSTEM BACKGROUND OF THE INVENTION 1 Field This invention relates in general to fluid flow control apparatus for filter units used in connection with filtration systems, and more particularly to a unitary device, comprising a portion of the structural arrangement of each individual unit, for controlling the direction and rate of fluid flow within the unit, and wherein the filter units are of either the single filter element type or the multi-filter element type.

2 Prior Art Among the various designs and types of filter units and filtration systems having apparatus for controlling the flow of the fluid therein and currently known to applicant, the most common is of the type wherein the fluid control apparatus comprises a series of piping, or tubing, and a plurality of associated individual valves all located external of the filter unit, or system.

It is noted that numerous disadvantages are inherent in the above-described fluid flow control apparatus, thereby creating inconvenience and dissatisfaction with respect to the user. The more obvious of these disadvantages are namely: the system is both complicated and awkward in operation due to the piping arrangement and plurality of valves that must be incorporated therewith; the combination of the external piping and valve arrangement creates a large number of fittings and attachments that must be individually sealed to prevent leakage of both air and liquid; the piping, valves and fittings are expensive, thus resulting in an overall costly system; when the system makes use of a circulating pump, occasions arise (such as replacing the filter elements), wherein it is difiicult but necessary to both prime the pump and purge the system of air; further, it is difficult to improve the filtering efficiency of the system such as by increasing the number of filter elements therein, without adding costly material and equipment.

As applied to filter units, the primary object of the present invention is to provide an improved, simple, reliable, efficient and economical fluid flow control apparatus of a combined and unitary design for use therewith.

Another object of the present invention is to provide novel fluid flow control apparatus of a unitary design and specific configuration to readily enable the apparatus to be incorporated into the structural arrangement of a filter unit and form a permanent portion thereof.

A further object of the present invention is to provide novel fluid flow controlapparatus of a unitary design having internally formed ducts, valve channels and valves for controlling both the direction and rate of fluid flow in a filter unit, and wherein the flow control apparatus provides the housing portion of each valve structure.

SUMMARY OF THE INVENTION In the achievement of the above-mentioned objects and in accordance with a preferred embodiment of a practical application of the invention, there is provided a fluid filtration unit, comprising essentially a flat square-shaped base portion having a hollow elongated cylindrical body portion, or sleeve, securely mounted at one end to the top surface of the base, with at least one elongated filter element positioned at one end to the top surface of the base within the cylinder. A top portion, similar in shape to the base, is securely mounted to the other or top end of the cylinder for engaging the other end of the filter element, simultaneous with the mounting of the top thereon.

Anchor bolts, of a length slightly greater than the total length of the cylinder and the thickness of the base and top, are permanently attached at one end to each of the corners of the base and extend upwardly therefrom in a plane parallel with the outside of the cylinder. Before the top portion is mounted on the cylinder an adjustable clamp, of substantially the same inside diameter as the outside diameter of the cylinder and having ears, each with a slightly over-sized hole therein, permanently attached to the outside of the clamp at positions corresponding to the anchor bolts, is placed over the cylinder with each ear hole engaged by a corresponding anchor bolt. The clamp is then slid down over the cylinder to a position near but not touching the top surface of the base, whereupon the clamp is tightened around the cylinder by means of a screw or bolt to securely grip the outside surface of the cylinder. Nuts provided on each anchor bolt are thereafter tightened down onto each corresponding ear to press the cylinder down against the base for maintaining a combined fluid and air-tight seal with respect thereto. The top portion, which is provided with a slotted hole at each corner, is placed over the top or other end of the cylinder, with each anchor bolt extending through the corresponding slotted hole and thereafter securely fastened in place by means of wing nuts to maintain a fluid and air-tight seal thereat.

In addition to providing the mounting for the above-named parts of the system, the base portion is arranged with a network of internal ducts and internal valve chambers and valves, associated therewith, for controlling both the direction and rate of fluid flow within the system.

Briefly, in accordance with the invention, the base comprises essentially a flat square-shaped block of sufiicient thickness to enable the drilling of a plurality of holes inward from each of the four sides thereof, in a plane parallel to the top and bottom surfaces, with certain ones of the holes being of different predetennined lengths. Certain of the holes that are drilled in the first, second and third sides of the base form an interconnected network of fluid conducting ducts, while the other holes that are drilled in the second and fourth sides form a plurality of valve channels, each of which extends into and ends in a different one of each of the ducts. The outer ends of the holes in both the first and third sides of the base are threaded to accommodate coupling type fittings. Separate filtrate return and dump hoses, or tubing, are attached to the first side fittings, while the third side fittings are joined externally by a T-shaped coupling, with an inlet hose or tube attached to the leg of the T and extending to the outlet port of a pump. Each valve channel is threaded at its outer end to accommodate a correspondingly threaded valve stem having a plug shaped inner end. Thus, as each valve stem is moved inward or outward in its individual valve channel, the corresponding plug end will either close or open the duct associated therewith.

A plurality of relatively large diameter holes, equally spaced above the internal ducts and of a shallow depth are drilled in the top surface of the base, and a bottom filter element seat plug is force-fit into each hole. A hole of a smaller diameter is thereafter drilled through the center of each seat plug and down into the below-located ducts. A corresponding number of hollow-cored filter elements are vertically mounted in the system with one end of each element engaging a different one of the seat plugs.

Therefore, with the system arranged as described above, and with certain ones of the valves in the open position and the other ones in the closed position, fluid entering the system is directed by a particular inlet duct into the cylinder, through the filter elements from the outside, down into the main duct work, out through the return outlet duct to the filtrate return hose and to a filtrate, or fluid, storage tank. With the positions of the two groups of valves being reversed, backwash fluid enters the main duct work by way of a different inlet duct, passes up and through the filter elements from the inside, into the cylinder, out through the dump outlet duct to the dump outlet hose and to a waste drain.

DESCRIPTION OF THE DRAWINGS The nature of the invention and its distinguishing features and advantages, which reside in the construction and arrangement and combination of parts thereof, will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a partly sectioned and partly exploded isometric view of the filter unit;

FIG. 2 is a plan view of the base as viewed from the top of FIG. 1 with the top portion removed, showing in cross-section the apparatus mounted on the base, and showing in dotted lines the ducts and valves contained within the base and a particular position of the valves;

FIG. 3 is a plan view of the base, similar to FIG. 2, but showing in dotted lines a different position of the valves;

FIG. 4 is a partly sectioned and partly exploded isometric view of a modification of the filter unit, incorporating a single filter element;

FIG. 5 is a plan view of the base as viewed from the top of FIG. 4 with the top portion removed, showing in cross-section the apparatus mounted on the base, and showing in dotted lines the ducts and valve contained within the base; and

FIG. 6 is a diagrammatic representation showing a practical application of the filter unit, having the control apparatus installed therein, as used in a filtration system.

DETAILED DESCRIPTION 1. Structure.

Before proceeding with the detailed structural description of the fluid flow control apparatus as incorporated in the filter unit of a filtration system, it is first pointed out that one preferred practical application of the invention would be such as its use in the continuous filtering of electroplating solutions, wherein it is desired to keep these solutions substantially free from all filterable impurities at all times. In view of the abovesuggested application and the possibility that other acid solutions, or the like, may be filtered by this system, it is particularly desirable that the solution not be exposed to any metallic parts. Therefore, all the essential parts of the system, with the exception of the later-described filter elements, are constructed of various plastic materials such as those formed by chemical polymerization. Since these plastics, or polymers, have certain inherent characteristics, the particular requirements of each part in the system determines, to some extent, the selection of the polymer most suitable for its use therein. As an example, and referring to FIG. 1 of the drawings, it will be noted that base 1, top cover 3, plug 7, plug 16, deflector tube 13, top filter seats 5, and base filter seats 34 may consist of a polymer of the class such as polypropylene; valves 15, 17, 20 and 21 may consist of a self-lubricating polymer of the class such as tetraethylchloride; gaskets 6 and 28 and ring 38 and 38 may consist of a syn-thetic material of the class such as butane rubber; hose fittings 18, 19, 22 and 23 may consist of a polymer of the class such as polyethylene; and cylinder 2 may either consist of a transparent polymer of the class such as polycarbonate, or of the above-mentioned polypropylene.

It is also pointed out with reference to FIG. 2 of the drawings that the dotted lines in base 1 represent the internal duct work, valve channels, control valves, and the specific positions of the control valves when they are set for the filter operation, with the arrows indicating the path taken by the fluid in its passage through the filter unit. The dotted lines in FIG. 3 are similar to those in FIG. 2, with the exception that the control valves are set for the backwash operation and the arrows indicate a different path taken by the backwash fluid through the filter unit.

With reference to FIGS. 1, 2, 3 and 6, it is further pointed out that wherever possible, like parts have been given the same reference character number, while similar parts in the modification shown in FIGS. 4 and have been prefixed with the number 100. For example, filter elements 4 and anchor bolts of FIG. 1 have been designated as filter element 104 and anchor bolts 1 10 in FIGS. 4 and 5, respectively.

Referring for the moment to FIG. 6, it will be seen that a functioning filtration system comprises a filter unit, tank for filter solution, tank for backwash liquid, motor, pump and the necessary hoses or tubing whereby, during a filtering operation, the pump can circulate the filter solution from the tank through the filter unit and back to the filter tank. In the case of the backwash operation, the backwash liquid is directed by means of the dump hose to a waste drain and is not reused. The pump such as used in this system is preferably a magnetically driven centrifugal pump of the type such as disclosed in US. Pat. No. 3,306,221, issued Feb. 28, 1967, to Kenneth Wayne Goodpasture. In this particular type pump, the pump housing, or chamber, and the impeller also consist of a polymer of the class such as polypropylene.

A detailed description of the structure of the invention in its preferred form will now be given, reference being had with FIGS. 1 through 3, inclusive. The base 1 of the filter unit comprises a flat square-shaped block of sufficient thickness, whereby a plurality of holes are drilled inward from each of the four side edges to form an interconnected network of ducts, and to form valve channels, each ending in a different one of the ducts.

More specifically, and referring in particular'to FIGS. 2 and 3, the first duct drilled into base 1 is pilot duct 43, which is positioned in the center of the top side and extends into base 1 for a distance approximately equal to three-fourths of its total width. Filtrate return duct 45, is then drilled from the center of the left-hand side of base 1, and extends therein for a distance equal to that of pilot duct 43, thereby intersecting with this duct. Backwash inlet duct 29 and filter inlet duct 30 are thereafter drilled from the respective upper and lower portions of the right-hand side of base 1, with backwash duct 29 extending into and ending in pilot duct 43 and inlet duct 30 extending into base 1 for a distance approximately equal to one-third of the total width. Dump duct 41 is drilled into the lower portion of the left-hand side of base 1 and extends therein for a distance approximately equal to one-third of its total width. It will be appreciated that all ducts are of the same diameter. The outer end of pilot duct 43 is threaded to accommodate threaded plug 16, which is inserted and tightened therein to form a permanent fluid and air-tight seal. The outer ends of dump duct 41, return duct 45, backwash duct 29 and filter duct 30 are each threaded to accommodate the threaded ends of fittings 22, 23, 18 and 19, respectively, which are inserted and tightened therein. A portion 37, comprising a part of each fitting, is provided for tightening the fittings against base 1, whereby the 0" rings 38 form a liquid and air-tight seal therewith.

The control valve channels are thereafter drilled into base 1, with it being pointed out that while the diameters of all the control valve channels are the same, their diameters are substantially greater than that of the ducts for the purpose of allowing the later-installed valves to completely ,block their associated ducts, when the respective valves are closed. Return control valve channel 44 is drilled into the left-hand portion of the top side of base 1 and extends down into and slightly beyond filtrate return duct 45. Backwash control valve channel 42 is drilled into the right-hand portion of the top side of base 1 and extends down into and slightly beyond backwash inlet duct 29. Filter control valve channel 31 is drilled into the right-hand portion of the lower side of base 1 and extends up into and slightly beyond filter inlet duct 30. Dump control valve channel 32 is drilled into the left-hand portion of the lower side of base 1 and extends up into and slightly beyond dump duct 41. The outer ends of valve channels 44, 42, 31 and 32 are each threaded to accommodate the threaded portions of filtrate return control valve 15, backwash control valve 17, filter control valve 20 and dump control valve 21, respectively, which are inserted therein. Each control valve has a circular groove formed in their circumference between their threading and the plug end for accommodating 0 rings 38, whereby a liquid and air-tight seal is maintained regardless of whether the control valves are in either an open or closed position.

The top surface of base 1 is now prepared as shown in the drawings by drilling four shallow depth holes of such a diameter that a base seat plate 34 can be force-fit into each hole. Center holes 35, of a diameter corresponding to that of the ducts, are drilled in the center of each base seat plate 34 and extend down into the below-located ducts. More specifically, seat plates 34 are so located on base 1 that two of the opposing holes 35 extend down into pilot duct 43, and the other two opposing holes 35 extend down into return duct 45. Dump hole, or port 33, which is of the same diameter as holes 35, is drilled into the top surface of base 1 and extends down into the end of dump duct 41. As shown in FIGS. 2 and 3, a hole, or inlet port, for receiving deflector tube 13 is drilled down into filter inlet duct 30 at a position to the left of filter control valve channel 31, with this hole being threaded and the threaded end of deflector tube 13 being tightened therein. Deflector tube 13 is so positioned that the rows of deflector holes 36 face toward anchor bolt in the right-hand comer of base 1. The upper end of deflector tube 13 is covered by cap 14. A circular groove 39, of substantially the same wall thickness and diame ter as cylinder 2, and encircling all the seat plates 34, dump hole 33 and deflector tube 13, is formed in the top surface of base 1 to a depth that will accommodate both base gasket 28 and a portion of one of the wall ends of cylinder 2. A hole 33 is drilled through each corner of base 1, external of circular groove 39, and an anchor bolt 10 is securely mounted in each hole by means of individual pairs of nuts 27. It will be noted that the inward facing surfaces of base seat plates 34 are shaped to accommodate correspondingly shaped ends of stan dard type filter elements.

Top seat plates 5 are mounted in the bottom surface of top cover 3 in the same manner as that described for the mounting of base seat plates 34, with the exception that no holes drilled into their centers. Top seat plates 5 must be so positioned on cover 3 that upon final assembly of the unit, each top seat plate 5 will be directly above a corresponding base seat plate 34. A circular groove 59 is also formed in the bottom surface of top cover 3 in the same manner as described for the forming of groove 39 in base 1. A vent, or fill, hole 8 is drilled through top cover 3 at a position inside groove 59 and is threaded to accommodate the threaded portion of vent, or fill, plug 7. A hole 12 is drilled through each corner to top cover 3, with a slot 11, of a sufficient width to allow the anchor bolts 10 to slide through, being cut into each hole from each corresponding corner.

Upon assembly of the filter unit, a hollow-cored filter element 4 is placed in a vertical position over each base seat plate 34 with the filter ends in engagement therewith. Base gasket 28 is fitted into groove 39 and cylinder 2 is positioned around the filter elements 4, with the lower end wall portion of cylinder 2 fitting into groove 39 and resting on top of base gasket 28. Cylinder securing clamp 24 is then positioned around cylinder 2, with each of the anchor bolts 10 protruding through an enlarged hole provided in each ear 25, which are permanently attached to clamp 24. Clamp 24 is lowered down on cylinder 2 to a point near, but not touching the top surface of base I, at which time, clamp screw 40 is tightened to cause clamp 24 to securely grip cylinder 2. The enlarged holes in each ear 25 allows sufficient movement of clamp 24 to grip cylinder 2 as screw 40 is tightened. Nuts 26 are thereafter tightened down against each ear 25 to securely press the end wall of cylinder 2 against gasket 28 and base 1, in order to provide both a liquid and air-tight seal. Top gasket 6 is then inserted in top cover .groove 59, with top cover 3 being positioned over cylinder 2, filter elements 4 and anchor bolts 10 so that the upper end wall of cylinder 2 fits into groove 59 and rests against gasket 6. At this time, the top ends of each filter element 4 engage a corresponding top seat plate 5 and each anchor bolt 10 extends through a corresponding hole 12. Wing nuts 9 are thereafter tightened down on the anchor bolts 10 with the wing nuts exerting pressure against the top surface of top cover 3 to cause a fluid and air-tight seal with respect to the upper end wall of cylinder 2.

While the above description covers the installation and use of a maximum of four of the filter elements 4 in the filter unit, it will be appreciated that any number of from one to four of these filter elements 4 can be used in this unit. As an example, if it is determined that only one filter element 4 is needed,

each of the holes 35 in the three remaining base seat plates 34 may be plugged by inserting a stopper (not shown) of a composition such as butane rubber tightly therein. As an alternative, the holes 35 may be threaded (not shown) and a threaded plug (not shown) of a composition such as polypropylene tightened therein.

Referring now in particular to FIGS. 4 and 5, it will be seen that the modification shown therein represents a filter unit of the single filter element type, with the overall structural arrangement being quite similar to that of the multi-filter element type as previously described. However, it will be appreciated that due to the reduced size of the base, the use of a single filter element, the specific ducts and the single control valve and associated valve channel, the function of this filter unit is limited only to that of filtering, while backwashing of the filter element is not provided. It will be appreciated that the dotted lines shown in FIG. 4 represent an initial position of the top cover 103 before it is rotated to the final assembly position, or the position to which it is first rotated, before removal from cylinder 102. The dotted lines in FIG. 5 represent the location of the ducts, valve channel and valve in the base 101, and the arrows indicate the direction of the passage of the filter solution through the unit.

More specifically, and referring in particular to FIG. 5, filter inlet duct is drilled from the center of the right-hand side of base 101, and extends therein for a distance approximately equal to one-fourth of its total width. Filtrate return duct 145 is drilled from the center of the left-hand side of base 101 and extends therein for a distance slightly beyond one-half of its total width. Although not shown, a base seat plate similar to plate 34 (FIG. 1) is mounted in the center of the top surface of base 101, and a hole of the same diameter as ducts 130 and is drilled through the base seat plate and'down into return duct 145. A filter inlet hole is drilled from the top surface of base 101 and down into the end of inlet duct 130. Control valve channel 131 is drilled into the right-hand portion of the lower side of base 101 and extends up into and slightly beyond inlet duct 130. Although FIG. 5 is for illustration only, it will be appreciated that the actual diameter of control valve channel 131 is slightly greater than that of ducts 130 and 145 for the same reasons as mentioned in the description for the multi-filter element type of filter unit, and shown in FIGS. 1, 2 and 3.

The outer ends of ducts 130 and 145 are threaded and equipped with fittings 119 and 123, respectively, in the same manner as previously described for the multi-filter element unit. The outer end of control valve channel 131 is threaded and fitted with filter control valve 120, and circular groove 139 is formed in base 101 also as previously described. Instead of a deflector tube, deflector washer 151, having a suitable inner diameter, is positioned over the base seat plate (not shown) and the filter element 104 is mounted thereon. Top cover 103 is also provided with a top seat plate, top groove, top gasket, (all not shown), holes 112, vent or fill plug 107, vent or fill hole 108 and slots 111. The single filter unit is thereafter completely assembled in the same manner as described for the multi-filter element filter unit.

2 Operation An operational description of the invention as disclosed in a practical application thereof will now be given, reference being had with FIGS. 1-3, inclusive, and FIG. 6, which show the multi-filter element filter unit as used in a filtration system. It will be assumed that the filter unit is installed in a system such as shown in FIG. 6 and that both the unit and pump is empty, thereby making it necessary to first prime the pump.

Since it will be assumed that the system will first be operated in the filter function, reference to FIG. 2 shows that backwash control valve 17 and dump control valve 21 must be closed by turning them until the inner plug ends engage the ends of channels 42 and 32, respectively. Backwash inlet duct 29 and dump duct 41 will therefore be blocked by their respective control valves 17 and 21. Also, return control valve 15 and filter control valve 20 must be opened, whereby return duct 45 and inlet duct 30 are not blocked. Fill, or vent, plug 7 is removed from hole 8 and a suitable quantity of the filter solution is poured through hole 8 into the inside of the unit. The solution will tend to seek its lowest level, and by so doing will pass through the deflector tube holes 36, down deflector tube 13 into inlet duct 30, out through hose coupling 58, through pump outlet hose 46 and into the impeller chamber to thereby prime the centrifugal pump.

Motor 49 is now started and in turn drives the pump, causing it to draw the filter solution from tank 52 by way of intake hose 47 into the pump chamber. The filter solution is forced out of the pump chamber and into pump outlet hose 46, where it is directed by way of hose coupling 58 into inlet duct 30, up through deflector tube 13 and out holes 36 into the inside of cylinder 2. The filter unit thereupon, proceeds to fill cylinder 2, with air exiting vent hole 8 until none remains inside. At this time motor 49 is stopped and plug 7 is tightly installed in hole 8. The filtering operation may now take place, responsive to restarting the motor, with the solution entering the unit as previously described, wherein the deflector tube holes 36 cause the solution to be directed by means of the inner curved walls of cylinder 2 around the interior, as shown by the arrows in FIG. 2, through the filter elements 4, down their hollow cores into holes 35 and down into ducts 29 and 45, where the filtrate combines at the outer end of duct 45, enters into retumhose 48 and is returned to solution tank 52. In this continuous filtering of the solution, impurities from the solution will build up on the outside surface of the filter elements.

It will now be assumed that the outside surface of the filter elements 4 have become caked with the impurities and that it will be necessary to operate the system in the backwash operation to clean the elements. The motor 49 is therefore stopped to halt the filtering operation. Referring now to FIG. 3, it will be noted that backwash control valve 17 and dump control valve must be opened, and that return control valve 15 and filter control valve 20 must be closed, whereby backwash duct 29 and dump duct 41 will be open, and return duct 45 and inlet duct 30 will be blocked. Pump intake hose 47 is transferred from solution tank 52 to backwash supply tank 53 and motor 49 is restarted. Backwash liquid now leaves the pump by way of pump outlet hose 46, is directed by means of hose coupling 56 into backwash inlet duct 29, enters ducts 43 and 45, up through holes 35 into the cores of filter elements 4, through filter elements 4 into the interior of cylinder 2, out dump hole 33 into dump duct 41 and through dump hose 55 to an exterior waste drain.

It will be appreciated that the single element filter unit shown in FIGS. 4 and will operate similar to the priming, venting and filtering operations described above when connected in the system such as shown in FIG. 6, and such, it is not believed necessary to repeat these operations in detail. It is pointed out however, that control valve 120 must be in the open position for all operations, and that deflector washer 150 serves the same function as deflector tube 13, wherein the incoming solution is deflected by washer 120 against the interior walls of cylinder 102 to circulate within cylinder 102 before it passes through the filter 104 and subsequently exits. Control valve 120, however may be closed for filling the unit with the solution prior to priming of the pump, and then opened for priming.

It is pointed out that the filter elements are preferably of a cotton material formed around a perforated plastic tube, or core. Also, it is usually necessary that the outer surface of new filter elements, or those that have just been cleaned, must be coated with a particular substance before the element can efficiently be used in a filtering operation. This coating is accomplished by installing the filter element, or elements, in the unit, making a slurry consisting of the coating substance and pumping it through the filter unit in the same manner as if it were operating in a filter operation, whereby the outer surface of the element is coated by the substance in the slurry.

It will be seen that if it is desired to reduce therate at which the solution flows through the filter units, all that is necessary is to partly close the inlet control valves during the operations until the desired rate of flow is found.

In summation, it is thought that the invention, together with its numerous advantages and the achievement of the objects, will be fully understood from the foregoing description. It is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the true spirit or scope of the invention, or sacrificing any of its attendant advantages.

What is new and desired to have protected by Letters Patent will be pointed out in the appended claims.

I claim:

1. In a fluid filtration system; a filtering unit having a mounting base including a plurality of ducts and control valve channels each extending from the exterior sides therein, all in the same horizontal plane; an internal network of interconnected-J ducts formed within said base by certain ones of said plurality of ducts comprising a filtrate return duct, a pilot duct and a backwash duct; a filter inlet duct and a dump duct individually formed in said base by the respective remaining ones of said plurality of ducts; said filtrate return duct, said backwash duct, said filter inlet duct and said dump duct each having a different one of said plurality of control valve channels intersect ing at right angles therewith and ending therein at points located near their outer ends; a plurality of elongated hollowcored filter elements mounted at one end on the top of said base; means for connecting said filter element cores with said internal network; a filter inlet port extending from said top of said base into the inner end of said filter inlet duct; a dump exit port extending from said top of said base into the inner end of said dump duct; a hollow elongated cylinder mounted at one end to said top of said base and encircling said filter elements, said filter inlet port and said dump exit port; a top cover mounted on the other end of said cylinder and simultaneously engaging the other end of said filter elements; a valve stem rotatably mounted in each said control valve channel for longitudinal movement therein; each said valve stem having a plug-shaped inner end for blocking or unblocking each said duct associated with each said control valve channel, depending on the respective closed or open position of each said valve stem within its said associated channel; a filtering fluid route established in said filtering unit in response to the closing of certain ones of said valve stems and the opening of the remaining ones of said valve stems in their said associated channels, and extending from said filter inlet duct through said inlet port into said cylinder, through said filter elements from the outside into said cores, into said network and out said filtrate return duct; and a backwash fluid route established in said filtering unit in response to the opening of said certain ones and the closing of said remaining ones of said valve stems'in their said associated channels, and extending from said backwash duct into said network, into said core, through said filter elements from the inside into said cylinder, through said dump exit port and out said dump duct.

2. A fluid filtration system as claimed in claim 1; including a common inlet hose; means for externally joining both said filter inlet duct and said backwash duct to said common inlet hose; fluid storing means; a filtrate return hose connected to said filtrate return duct and extending to said storing means; and pumping means connected to said storing means and said common inlet for circulating said fluid through said filtering unit by way of said common inlet hose, said filtering fluid route and backover said filtrate return hose to said storing means in response to said closing of said certain ones of said valve stems and said opening of said remaining ones of said valve stems in their said associated channels.

3. A fluid filtration system as claimed in claim 1; including a common inlet hose; means for externally joining both said filter inlet duct and said backwash duct to said common inlet hose; backwash fluid storing means; a dump hose connected to said dump duct; and pumping means connected to said backwash storing means and said common inlet for circulating said backwash fluid through said filtering unit by way of said common inlet hose, said backwash fluid route and out said dump hose, in response to said opening of said certain ones of said valve stems and said closing of said remaining ones of said valve stems in their said associated channels.

4. A fluid filtration system as claimed in claim 1; including anchor means securely attached to said base outside of said cylinder; and clamp means securely gripping the outside surface of said cylinder near said one end, and tightly engaged by said anchor means for establishing a fluid and air-tight seal between said one end of said cylinder and said top of said base.

5. A fluid filtration system as claimed in claim 4; including means in said top cover tightly engaged by said anchor means for establishing a fluid and air-tight seal between said other end of said cylinder and said top cover.

6. In a filtration system, a filter unit comprising: a mounting base; a hollow elongated cylinder mounted with one end engaging the top surface of said base; anchoring means secured to said base outside said one cylinder end; clamping means securely gripping the outside of said cylinder near said one end, and engaged by said anchoring means for establishing a seal between said one end and said top surface of said base; a network of interconnected ducts formed within said base; a first inlet duct and a first exit duct formed within said base, each individually connected to said network; a second inlet duct and a second exit duct formed within said base, each individually extending through said top surface of said base within said one cylinder end; a plurality of valve channels formed within said base, each individually connected to a different one of said first inlet and exit ducts and said second inlet and exit ducts; a plurality of access holes extending into said base from said top surface within said one cylinder end, each ending in said network; a plurality of hollow-cored filter elements, each mounted at one end over a corresponding one of said access holes; a cover mounted over the other end of said cylinder and the other ends of said filter elements, and tightly engaged by said anchoring means for establishing a seal between said cover and said other cylinder end, and engaging said other filter element ends for holding said elements in position within said cylinder; a valve stem mounted within each of said valve channels, and movable in longitudinal directions to either of two predetermined positions therein;

a filtering route established through said filter unit in response to movement of said valve stems in said channels to one of said predetermined positions, and extending via said second inlet duct into said cylinder, through said filter elements from the outside into said cores, into said network and out said first exit duct; and a backwashing route established through said filter unit in response to movement of said valve stems in said channels to the other of said predetermined positions, and extending via said first inlet duct into said network, into said cores of said filter elements, through said filter elements from the inside, into said cylinder and out said second exit duct.

7. A filtration system as claimed in claim 6; wherein said anchoring means comprises a plurality of threaded bolts, each having a wing nut mounted on its upper end; and access means in said cover for engagement of said bolts therewith without removal of said wing nuts from said upper ends.

I l II! 

1. In a fluid filtration system; a filtering unit having a mounting base including a plurality of ducts and control valve channels each extending from the exterior sides therein, all in the same horizontal plane; an internal network of interconnected ducts formed within said base by certain ones of said plurality of ducts comprising a filtrate return duct, a pilot duct and a backwash duct; a filter inlet duct and a dump duct individually formed in said base by the respective remaining ones of said plurality of ducts; said filtrate return duct, said backwash duct, said filter inlet duct and said dump duct each having a different one of said plurality of control valve channels intersecting at right angles therewith and ending therein at points located near their outer ends; a plurality of elongated hollow-cored filter elements mounted at one end on the top of said base; means for connecting said filter element cores with said internal network; a filter inlet port extending from said top of said base into the inner end of said filter inlet duct; a dump exit port extending from said top of said base into the inner end of said dump duct; a hollow elongated cylinder mounted at one end to said top of said base and encircling said filter elements, said filter inlet port and said dump exit port; a top cover mounted on the other end of said cylinder and simultaneously engaging the other end of said filter elements; a valve stem rotatably mounted in each said control valve channel for longitudinal movement therein; each said valve stem having a plug-shaped inner end for blocking or unblocking each said duct associated with each said control valve channel, depending on the respective closed or open position of each said valve stem within its said associated channel; a filtering fluid route established in said filtering unit in response to the closing of certain ones of said valve stems and the opening of the remaining ones of said valve stems in their said associated channels, and extending from said filter inlet duct through said inlet port into said cylinder, through said filter elements from the outside into said cores, into said network and out said filtrate return duct; and a backwash fluid route established in said filtering unit in response to the opening of said certain ones and the closing of said remaining ones of said valve stems in their said associated channels, and extending from said backwash duct into said network, into said core, through said filter elements from the inside into said cylinder, through said dump exit port and out said dump duct.
 2. A fluid filtration system as claimed in claim 1; including a common inlet hose; means for externally joining both said filter inlet duct and said backwash duct to said common inlet hose; fluid storing means; a filtrate return hose connected to said filtrate return duct and extending to said storing means; and pumping means connected to said storing means and said common inlet for circulating said fluid through said filtering unit by way of said common inlet hose, said filtering fluid route and back over said filtrate return hose to said storing means in response to said closing of said certain ones of said valve stems and said opening of said remaining ones of said valve stems in their said associated channels.
 3. A fluid filtration system as claimed in claim 1; including a common inlet hose; means for externally joining both said filter inlet duct and said backwash duct to said common inlet hose; backwash fluid storing means; a dump hose connected to said dump duct; and pumping means connected to said backwash storing means and said common inlet for circulating said backwash fluid through said filtering unit by way of said common Inlet hose, said backwash fluid route and out said dump hose, in response to said opening of said certain ones of said valve stems and said closing of said remaining ones of said valve stems in their said associated channels.
 4. A fluid filtration system as claimed in claim 1; including anchor means securely attached to said base outside of said cylinder; and clamp means securely gripping the outside surface of said cylinder near said one end, and tightly engaged by said anchor means for establishing a fluid and air-tight seal between said one end of said cylinder and said top of said base.
 5. A fluid filtration system as claimed in claim 4; including means in said top cover tightly engaged by said anchor means for establishing a fluid and air-tight seal between said other end of said cylinder and said top cover.
 6. In a filtration system, a filter unit comprising: a mounting base; a hollow elongated cylinder mounted with one end engaging the top surface of said base; anchoring means secured to said base outside said one cylinder end; clamping means securely gripping the outside of said cylinder near said one end, and engaged by said anchoring means for establishing a seal between said one end and said top surface of said base; a network of interconnected ducts formed within said base; a first inlet duct and a first exit duct formed within said base, each individually connected to said network; a second inlet duct and a second exit duct formed within said base, each individually extending through said top surface of said base within said one cylinder end; a plurality of valve channels formed within said base, each individually connected to a different one of said first inlet and exit ducts and said second inlet and exit ducts; a plurality of access holes extending into said base from said top surface within said one cylinder end, each ending in said network; a plurality of hollow-cored filter elements, each mounted at one end over a corresponding one of said access holes; a cover mounted over the other end of said cylinder and the other ends of said filter elements, and tightly engaged by said anchoring means for establishing a seal between said cover and said other cylinder end, and engaging said other filter element ends for holding said elements in position within said cylinder; a valve stem mounted within each of said valve channels, and movable in longitudinal directions to either of two predetermined positions therein; a filtering route established through said filter unit in response to movement of said valve stems in said channels to one of said predetermined positions, and extending via said second inlet duct into said cylinder, through said filter elements from the outside into said cores, into said network and out said first exit duct; and a backwashing route established through said filter unit in response to movement of said valve stems in said channels to the other of said predetermined positions, and extending via said first inlet duct into said network, into said cores of said filter elements, through said filter elements from the inside, into said cylinder and out said second exit duct.
 7. A filtration system as claimed in claim 6; wherein said anchoring means comprises a plurality of threaded bolts, each having a wing nut mounted on its upper end; and access means in said cover for engagement of said bolts therewith without removal of said wing nuts from said upper ends. 